All the stuff that sounds awesome in large, but is funny/useful in smaller doses.
Making a person feel itchy - amusing when it's done to one or two people. Useful/disastrous if done to a whole mob or army. Same with headaches.
Or, creating light - impressive as a giant, blinding ball of light, useful as a smaller reading light for sneaking into libraries, studies and such.
Weird one- make cooked animals appear to speak - sort of specialized ventriloquism. No actual purpose, but if you aren't sensitive, it makes for lots of leftovers.
Also, the humorous side:
Rebel leader, from the crowd: "The king is a swine!"
Roasted boar, from the head table: "Hoi, don't you be blaming us, for the likes of him!"
Or: "Aye, he's one of us, get yer bloody spears, and the damned dogs."